Effect of Recurrent Coronary Artery Spasm on Left Ventricular Contractile Function

ABSTRACT

BACKGROUND: Myocardial contractile dysfunction is often noticed without myocardial infarction, it may be due to myocardial stunning or hibernation. There are several case reports of myocardial stunning in patients with variant angina, but effect of recurrent myocardial spasm on myocardial contratile function in human is not well established. METHODS: To evaluate the effect of recurrent spasm-induced myocardial ischemia on myocardial contractile function, we analyzed the ejection fraction(by area-length method) and regional wall motion(by centerline method) at before and after intracoronary nitroglycerin in variant angina group and control group. Variant angina group consisted of 15 patients(LAD ; 10 patients, RCA ; 5 patients) and normal control group consisted of 6 patients. RESULTS: Ejection fraction increment after nitroglycerin infusion was not significant in normal control group, but that in variant angina group was significant(p<0.05). Pre-NG shortening fraction of LAD territory on both RAO and LAO view in patients with spasm in LAD was significantly lower than that in patients without spasm in LAD(RAO ; p<0.05, LAO ; p<0.01). On LAO view pre-NG shortening fraction of LAD territory in 6 patients with spasm and without significant fixed lesion was lower than that in patients without spasm in LAD(p<0.05). Shortening fraction increment after nitroglycerin infusion in LAD territory on both RAO and LAO view was significant in patients with spasm in LAD(RAO ; 0.05, LAO ; p<0.01), but that in LCX or RCA territory and that in LAD territory of patients without spasm in LAD was not significant. Shortening fraction increment after nitroglycerin infusion in RCA territory on LAO view was significant in patients with spasm in RCA(p<0.05), but that in LAD or LCX territory and that RCA territory of patients without spasm in RCA and was not significant. CONCLUSION: These observations suggest that recurrent coronary artery spasm results in reversible dysfunction of the ventricular global and regional contractility, and myocardial stunning may be the cause of this phenmenon.